//2009/08/31 01:33:14
#include <iostream>
#include <string>
#include <vector>
#include <map>
#include <queue>
#include <math.h>
#include <sstream>
#include <algorithm>

using namespace std;

class IncredibleMachineEasy
{
public:
    double gravitationalAcceleration(vector <int> height, int T)
    {
		double dis = 0.0;
		for(int i=0; i<height.size(); i++)
			dis += sqrt(2.0 * height[i]);
		return dis * dis / T / T;
    }
};
